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2SD1781

Public Made by Adom

by adom

Changjing Bipolar (BJT), SOT-23. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.

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2SD1781

Changjing · Bipolar (BJT) · SOT-23

2SD1781 from Changjing, in a SOT-23. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 BASE input Base terminal of the 2SD1781 NPN transistor; the datasheet's maximum rated emitter-base voltage VEBO is 5 V.
2 EMITTER passive Emitter terminal of the 2SD1781 NPN transistor; the same 5 V maximum emitter-base voltage rating (VEBO) applies across the emitter and base.
3 COLLECTOR passive Collector terminal of the 2SD1781 NPN transistor; the datasheet's maximum ratings are VCBO 40 V, VCEO 32 V and collector current IC 800 mA.

Key specifications

Parameter Value
Manufacturer Changjing
Package SOT-23
Category Transistors/Thyristors
Pins 3

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
Collector-base breakdown voltage V(BR)CBO 40 V IC=50μA,IE=0 1
Collector-emitter breakdown voltage V(BR)CEO 32 V IC=1mA,IB=0 1
Emitter-base breakdown voltage V(BR)EBO 5 V IE=50μA,IC=0 1
Collector cut-off current ICBO 0.5 μA VCB=20V,IE=0 1
Emitter cut-off current IEBO 0.5 μA VEB=4V,IC=0 1
DC current gain hFE(1) 120 390 VCE=3V,IC=100mA 1
Collector-emitter saturation voltage VCE(sat) 0.4 V IC=500mA,IB=50mA 1
Transition frequency fT 150 MHz VCE=5V,IC=50mA,f=100MHz 1
Collector output capacitance Cob 10 pF VCB=10V,IE=0,f=1MHz 1
Collector-Base Voltage VCBO 40 V 1
Collector-Emitter Voltage VCEO 32 V 1
Emitter-Base Voltage VEBO 5 V 1
Collector Current IC 800 mA 1
Collector Power Dissipation PC 200 mW 1
Operation Junction and Storage Temperature Range TJ,Tstg -55 150 ℃ 1
Thermal Resistance From Junction To Ambient RΘJA 625 ℃/W 1

CAD (KiCad official)

  • Symbol: 2SD1781
  • Footprint: Package_TO_SOT_SMD:SOT-23
  • 3D model: SOT-23 (KiCad packages3D, STEP)
  • 3D model files: 2sd1781-etched.step / 2sd1781-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); 2sd1781.step / 2sd1781.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: Changjing datasheet (4 pp, sha256 b0d5a3f7653c931b, retrieved 2026-10-18, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF